Homu's comments should go on the author's repository

[barosl]

@huonw told me on IRC that it would be great for Homu to comment its status messages (like "build started", "build failed") on the author's repository, not on the PR. It is bors' current behavior.

The upside of this is that we get less emails. Only the relevant author will be notified. The (possible) downside I can imagine is that we will lose some history in case the PR is force-pushed.

What's your thoughts on this?

[huonw]

If the comments (or merge commit) include a reference to the PR number, github will put a link to that commit/comment in the PR, e.g. https://github.com/rust-lang/rust/pull/20997#ref-commit-e94a9f0 . These links are clickable even once the branch has been force pushed and so history can be retrieved that way (at least for a little while, until github GC's the old commits), but it should be long enough for most uses of that history.

[alexcrichton]

With the references that @huonw mentioned, this sounds like a great idea to try to reduce the noise of emails!

[Gankra]

I think we should also ping the reviewer, since they are in effect "sheparding" the PR. If they're in the mood they can peek at the log errors and decide if a retry is needed or something else.

[nagisa]

Alternative is for homu to edit its own message and separate edits by horizontal rule. It would work because edits won’t send more mail and AFAIK pinging in edits will.

<datetime> :hourglass: Testing…
---
<datetime> :broken_heart: @reviewer @author Failed!

(reviewer then retries and another status-message-edit-thread is started)

[njsmith]

We've been exploring using homu for numpy, and this is the major complaint from the more grumpy maintainers that would need convincing -- 3 extra emails per merge is too much spam.